Forebrain Anatomy and Limbic System Flashcards
(114 cards)
1
Q
What structures make up the Diencephalon?
A
Epithalamus
Thalamus
Hypothalamus
Subthalamus
2
Q
What structures make up the Epithalamus?
A
Pineal gland
Habenula
3
Q
Pineal gland
A
Secretes melatonin
4
Q
Mealatonin
A
Released during darkness
Regulates sleep-wake cycles
5
Q
Habenula
A
Paired structure near the base of the pineal gland
6
Q
Habenula major input
A
Stria medullaris (limbic input)
7
Q
Habenula major output
A
Habenulointerpeduncular tract to midbrain Reticular formation
8
Q
Thalamus borders
A
Lateral ventricle (superior) Internal capsule (lateral) Globulus Paladus (inferolateral) Hypothalamus (Inferior) 3rd Ventricle (Medial)
9
Q
Thalamus
A
“Gateway to the cortex”
Relay station for many pathways going to the cortex
10
Q
What pathways relay in the thalamus?
A
All sensory pathways (except olfaction)
Cerebellar pathways
Basal ganglia
Limbic systems
11
Q
T/F - Systems that relay in the thalamus mostly use different parts
A
True - So the thalamus is comprised of distinct nuclei
12
Q
What are the subdivisions of the thalamic nuclei?
A
Anterior division Medial division Lateral division Intralaminar Reticular nucleus Midline nucleus
13
Q
What is located in the Anterior division of the thalamus?
A
Anterior nuclei
14
Q
What is located in the medial division of the thalamus?
A
Dorsomedial nucleus
15
Q
What are the tiers of the Lateral division of the thalamus?
A
Dorsal tier
Ventral tier
16
Q
Divisions of the dorsal tier of the lateral division of the thalamus
A
Lateral dorsal
Lateral posterior
Pulvinar
17
Q
Divisions of the ventral tier of the lateral division of the thalamus
A
Ventral anterior
Ventral lateral
Ventral posterior
18
Q
Divisions of the Ventral posterior division of the ventral tier of the lateral division of the thalamus
A
Lateral geniculate nucleus
Medial geniculate nucleus
19
Q
What is part of the intralainar division of the thalamus
A
Centromedian
Parafascicular
others
20
Q
What defines the subdivisions of the thalamus?
A
Internal medullary lamina
21
Q
What makes up thalamic nuclei?
A
Projection neurons
Interneurons
22
Q
Projection neurons
A
Provide output from the thalamus
23
Q
Interneurons
A
Small, inhibitory neurons
24
Q
What are the basic types of thalamic input?
A
Specific inputs
Regulatory inputs
25
Specific inputs
Convey info a thalamic nucleus passes to the cortex
26
Regulatory inputs
Thalamic nucleus contributes to the info it receives before it is passed to the cortex
27
What are the basic types of thalamic nuclei?
Relay nuclei
Association nuclei
Intralaminar or midline nuclei
28
Relay nuclei
Receive well defined specific input from a subcortical source and project to a well-defined area of cortex
29
Association nuclei
Receive specific inputs from association cortex and project back
30
Intralaminar and midline nuclei
Receive distant set of specific inputs (basal ganglia, limbic structures) and project to cortex, basal ganglia, and limbic structures
31
Reticular nucleus
Sheet of neurons that covers the thalamus
Important source of regulatory input to the thalamus
Axons must traverse the nucleus to enter/leave the thalamus and sends collaterals to it
32
Reticular nucleus projections
No projections to the cortex - unlike all other thalamic nuclei
33
Reticular nucleus input
Cortex and thalamis
34
Reticular output
Inhibitory axons to thalamus
35
Where are the sensory system relay nuclei?
VPL
| VPM
36
Where are the motor system relay nuclei
VA
| VL
37
Where are the limbic system relay nuclei?
AN
| LD
38
Hypothalamus function
Critical in autonomic, endocrine, emotional, and somatic functions
Maintains physiologic range or homeostasis
39
What are the connections of the Hypothalamus?
Interconnected with limbic system
Output to pituitary
Interconnects visceral and somatic nuclei
40
Hypothalamus contents
Optic chiama
Infundibular stalk
Mammillary body
41
Hypothalamus longitudinal divisions
Anterior region
Tubular region
Posterior region
42
Hypothalamus Medial-Lateral Organization
Lateral
Periventral
Medial
43
Lateral division of Hypothalamus
Rostral continuation of the reticular formation
| Contains nuclei and tracts
44
Periventral division of Hypothalamus
Rostral continuation of periaqueductal gray
| Contains nuclei and tracts
45
Medial division of Hypothalamus
Contains nuclei
46
Suprachiasmatic nucleus location
Periventricular zone of the Anterior region of the hypothalamus
47
Suprachiasmatic nucleus fuctions
Gets direct renal input
Master clock of our circadian rhythms - on a 25 hr cycle that is reset by daylight
Has melatonin receptors and is responsible to pineal gland activity
48
Paraventricular nucleus location
Medial zone of the Anterior region of the hypothalamus
49
Paraventricular nucleus function
Elaborate hormones that travel down axons and are released in neurohypophysis
50
Supraoptic nucleus function
Elaborate hormones that travel down axons and are released on neurohypophysis
51
Supraoptic nucleus location
Medial zone of the Anterior region of the Hypothalamus
52
Lateral Preoptic nucleus location
Lateral zone of Anterior region of the Hypothalamus
53
Lateral Preoptic nucleus function
Promotes sleep
54
Arcuate nucleus location
Periventricular zone of Tuberal region of Hypothalamus
55
Arcuate nucleus function
Involved in feeding behaviors
56
Tuberomammillary nucleus location
Lateral zone of tubular region of the Hypothalamus
57
Tuberomammillary nucleus function
Diffuse histaminergic projections to cerebral cortex and thalamus
Activity of these projections is likely inhibited by some types of antihistamine drugs
58
What are the 2 key areas of Hypothalamic input
Parts of forebrain (especially the limbic system)
| Brainstem and Spinal cord
59
Forebrain connections to the hypothalamus
Convey info needed for the hypothalamus to mediate autonomic/somatic aspects of emotional states
60
Brainstem and spinal cord connections to the hypothalamus
Convey visceral and sensory information
61
Hippocammpus connection to the Hypothalamus
via the fornix
62
Amygdala connection to the Hypothalamus
via the Stria terminals and Ventral amygdofugal pathway
63
Hypothalamic ouputs
Use the same pathways as the inputs
| Cortical outputs end diffusely
64
What hormones are part of the Hypothalamus control of the pituitary?
```
Antidiuretic hormone (vasopressin)
Oxytocin
```
65
Antidiuretic hormone
Increases water reabsorption
| Decreases urine output
66
Oxytocin
Contraction of uterine and other smooth muscles
67
Limbic System function
Drive-related and emotional behaviors
68
Limbis system contents
```
Cingulate gyrus
Parahippocampal gyrus
Hippocampus
Amygdala
Septal Nuclei
```
69
Amygdala location
In anterior, medial temporal lobe
| Merges with periamygdaloid cortex
70
What are the three nuclear groups of the amygdala?
Medial
Central-hypothal
Basolateral-cortex and central nuclei
71
Medial nuclear group of Amygdala function
Olfaction
72
Central-hypothal nuclear group of Amygdala function
Emotional responses
73
Basolateral cortex of Amygdala function
Emotional responses
74
From where does the Amygdala receive inputs for general sense of emotional and physical comfort/discomfort?
From orbital cortex and cingulate
75
From where does the Amygdala receive inputs for visceral sensory?
From Brainstem, PAG, and others
76
From where does the Amygdala receive input for Vision, taste, hearing, and somatosensory?
From cortex and thalamus
77
From where does the Amygdala receive input for olfaction?
Olfactory bulb and cortex
78
What are the 4 routes for amygdala input?
Stria terminalis
Ventral amygdalofugal pathway
Lateral olfactory tract
Directly from temporal lobe cortex and hippocampus
79
Stria terminalis
From hypothalamus and septal nuclei to amygdala
80
Ventral amygdalofugal pathway
From thalamus, hypothalamus, orbital and anterior cingulate cortex to the amygdala
81
Lateral olfactory tract
From olfactory bulb and olfactory cortex to amygdala
82
What are the amygdala outputs?
Stria terminalis
VAG pathway
Ventral striatum
83
Amygdala output to the ventral striatum
Meason for drive-related information to influence decisions about movement
84
Limbic Loop in basal ganglia
Drive-related information to influence movement/behavior
Associates stimuli with rewards
Pleasure results in increased ventral striatum dopamine release
85
Amygdala function
Links perception of object/situation with correct emotional response - especially in the case of danger
86
Thalamus and cortex inputs to amygdala function
Inform the amygdala about situations or objects in the environment
87
Hypothalamus and limbic system inputs to amygdala function
Informs the amygdala about current physiological and emotional state
88
Amygdala outputs to Ventral striatum, hypothalamus and brainstem initiate...
Emotional response
89
Amygdala output to cortex initiates...
An increase of awareness
90
Amygdala output to limbic system...
Contributes to emotional experience
91
Kluver-Bucy Syndrome cause
Bilateral temporal lobe injury involving the amygdala and parahippocampal gyrus
92
Kluver-Bucy Syndrome symptoms
Fearless
No emotional reactions
Don't flee or respond to threats from others
Males become hyper sexual and indiscriminate to sexual partners (can be inanimate objects or other species)
Inordinate sensation to all sensory stimuli
May pick up same object repeatedly and recognize nothing
93
Bilateral removal of Hippocampus causes:
Impaired declarative memory, and cannot form new episodic memories or semantic memories
94
Episodic memories
Past personal experiences
95
Semantic memories
Ideas or concepts not related to personal experiences (i.e. State Capitals)
96
Henry Molaison
Patient that had surgery to control his epilepsy
After the surgery, he could not consolidate and store long-term memories
He could remember things from before the surgery, and everything else was functioning normally
97
Fornix
A long course under the corpus callosum
| An important hippocampal output pathway
98
What are the zones of the Hippocampus?
Dentate gyrus
Hippocampus Proper
Subiculum
99
Subiculum
Transition between hippocampus proper and adjacent parahippocampal cortex
100
Entorhinal cortex projects to...
Dentate gyrus
101
Dentate neuron projects to...
CA3
102
CA3 neuron projects to...
fibriam and CA1
103
Subiculum projects to
Fimbria
104
Subicular neuron projects to...
Entorhinal cortex
105
Entorhinal neuron projects to...
Sensory cortex
106
Papez circuit
Interactions among limbic structures, cortex, and hypothalamus
Emotional experiences are processed memory
107
Medial geniculate nucleus function
Relay nucleus for hearing
108
Lateral geniculate nucleus function
Relay nucleus for vision
109
Ventral posterior medial nucleus function
Sensory relay nucleus for the face
110
Ventral posterior lateral nucleus function
Sensory relay nucleus for the body
111
Ventral anterior nucleus function
Motor relay nucleus
112
Ventral lateral nucleus function
Motor relay nucleus
113
Anterior nucleus function
Relay nucleus for the limbic system
114
Intralaminar nucleus function
Component of reticular activating system
